Apparatus for making composite board product



April 3, 1962 R. CHAPMAN 3,028,293

APPARATUS FOR MAKING COMPOSITE BOARD PRODUCT Original Filed March 26,1956 2 Sheets-Sheet 1 IN V EN TOR.

RALPH CHAPMAN BUCKHORN, CHEATHAM 8 BLORE ATTORNEYS April 3, 1962 R.CHAPMAN 3,023,293

APPARATUS FOR MAKING COMPOSITE BOARD PRODUCT Original Filed March 26,1956 2 Sheets-Sheet 2 IN V EN TOR.

RALPH CHAPMAN BUCKHORN, CHEATHAM a BLORE ATTORNEKT United States Patent3,028,293 APEARATUS FOR MAKING COh [POSITE BOARD PRODUCT Ralph Chapman,Corvallis, Greg, assignor to Wood Processes, Oregon Ltd., Corvallis,0reg., a partnership Original application Mar. 26, 1956, Ser. No.573,897, now

Patent No. 2,947,654, dated Aug. 2, 1960. Divided and this applicationNov. 3, 1959, Ser. No. 850,580

6 Claims. (Cl. 156-372) This application is a division of my co-pendingapplication Serial No. 573,897, filed March 26, 1956, now Patent No.2,947,654, granted on August 2, 1960, which in turn is acontinuation-in-part of my co-pending application Serial No. 487,753,filed February 14, 1955.

The present invention relates to apparatus for forming composite boardproducts from wood particles such as flakes of veneer, sawdust, hogfuel, chips, shavings and the like. A preferred form of product asdisclosed and claimed in the above-identified applications is formed ofveneer flakes and a suitable adhesive compacted together between surfaceskins of consolidated interlaced cellulosic fibers, the final producthaving a density in the order of 0.5 to 0.75; however, it is to beappreciated that the present invention may be utilized in themanufacture of other types of board products composed essentially ofdiscrete wood particles.

The object of the present invention is to provide apparatus foruniformly depositing the discrete particles on caul plates or othersuitable means to maintain the soformed deposit in mat form so that itmay be subjected to heat and pressure to consolidate the loose mass intothe final product.

The foregoing will be more readily understood by reference to theaccompanying drawing taken in connection with the followingspecification, wherein like numerals refer to like parts throughout andin which a form of the apparatus of the present invention is illustratedand described.

In the drawing:

FIG. 1 is a plan view of a portion of a composite board product made byapparatus including the present invention;

FIG. 2 is a side view of a portion of the product, showing the edgestructure thereof;

FIG. 3 is a plan view of a typical veneer flake embodied in the boardproduct;

FIG. 4 is a perspective view of a wood block from which the veneerflakes are formed showing two manners of slicing the block to form theveneer flakes;

FIG. 5 is a vertical section through a schematic representation of oneform of machine in which wood blocks may be diagonally sliced intoveneer flakes;

FIG. 6 is a side elevation, with parts broken away on a vertical centralplane, of a schematic representation of one form of equipment forapplying adhesive to veneer flakes or other wood particles;

FIG. 7 is a vertical section through a schematic representation of aform of cylinder machine for forming wet blankets of cellulosic fiberutilized to provide the surface skins of one type of board product whichmay be made in equipment utilizing the present invention; and

FIG, 8 is a vertical section through a schematic representation of oneform of equipment for forminga sand wich of veneer flakes or other'woodparticles between wet blankets of cellulosic fiber, the equipmentincluding the apparatus of the present invention.

In forming the product as illustrated, veneer flakes are sliced fromwaste wood, such as mill ends of lumber, scraps from furniture.factories, slab wood or logs. It is preferable to use blocksapproximately two inches thick, three inches long with the grain, and ofany width, the

blocks being cut for this purpose from mill ends of lumber by means ofgang saws. These blocks are best formed from lumber which has beensoaked or steamed, or are still in the green condition, so as normallyto contain about thirty to fifty percent water by weight. A typicalblock is shown in FIG. 4. A plurality of these blocks are oriented andfed successively into a machine for slicing them into veneer flakes,such as schematically illustrated in FIG. 5, this machine comprising afeeding mechanism including a driven, endless belt 1 forming the bottomof a trough, and a pair of such driven, endless belts forming the sidesof the trough, such as the one indicated by the numeral 2. The angle ofthe trough may vary from nothing to sixty degrees. It will be seen thatslicing the block on the diagonal, along the lines 3 in FIG. 4, resultsin the formation of a number of veneer flakes of variable width,uniformly the length of the block, and uniformly thick, the preferredflake ranging in width up to three or four inches. The flake-s may rangein thickness from 0.010 to 0.030 inch in thickness with an optimumthickness of approximately twenty thousandths of an inch. While it maybe desirable to employ diagonal slicing so as to form a certainpercentage of narrow veneer flakes, it is not necessary, and veneerflakes may be formed by vertical slicing along the lines 4 indicated inFIG. 4. Each veneer flake 5, however formed, will have the grain of thewood extending longitudinally as indicated by the alternate growth rings6 and soft wood 7 in FIG. 3, so as to be straight-grained.

The driven belts 1 and 2 of the veneer flake slicing machinefrictionally force the blocks against the face of a cutter disc 8 whichis mounted upon a shaft 9 extending to one side and connected to anysuitable source of power through a speed controlling means (not shown)whereby the number of veneer flakes produced per increment of time maybe controlled. The disc is provided with several openings 10, adjacenteach of which are provided veneer flake slicing knives 11 which slicethe blocks into the veneer flakes 5. The thickness of the veneer flakesis uniformly controlled by variably setting the projection of the knifeedges with respect to the face of the cutter disc against which theblocks rest between engagement by the knives. The veneer flakes soformed are propelled by fan blades 12 fixed to the disc 8 into anexhaust tube 13 by means of which the veneer flakes are conducted to anadhesive applying mechanism schematically illustrated in FIG. 6.

The tube 13 conducts the moist veneer flakes into the upper end of atumbling cylinder 14 which is inclined downwardly away from the tube andis provided with any suitable interior construction whereby the veneerflakes are alternately lifted and permitted to fall through the interiorof the cylinder while traversing its length. Adjacent the upper end ofthe cylinder is an adhesive supply bin 15 in which there is a supply ofdry powdered adhesive as indicated at 16. At the bottom of the bin 15there is provided an adhesive metering device schematically illustratedby an endless belt conveyor 17 having spaced lugs 18 thereon, each ofwhich pushes a certain amount of adhesive out of the bin and dischargesit into the upper end of the tumbling cylinder, the rate of dischargebeing controlled by variable speed drive means (not shown) connected tothe driving roll for the conveyor 17.

While any suitable form of adhesive could be utilized, it is preferred,for reasons of economy, ease of handling storage life, and quality offinished product, that a powdered protein adhesive be used. Whilenumerous such adhesives exist, such as casein glue and the like, it ispreferred that a soya bean adhesive, preferably raw soya bean flour, beutilized. From about five to about fifteen percent by weight of dryadhesive to the weight of dry wood is introduced, about ten percentbeing economical and giving desired strength and other qualities. Thetumbling of the moist veneer flakes together with the dry, powderedadhesive causes the veneer flakes to be uniformly coated throughouttheir surfaces with the adhesive. The coated veneer flakes drop from thelower end of the tumbling cylinder onto a conveyor belt 19 in a trough20, which conveyor belt conveys the veneer flakes to the formingequipment. At this point the veener flakes are adhesive coated veneerflakes indicated by the numeral 21.

The composite board product illustrated comprises the result ofconsolidating a sandwich of the adhesive coated veneer flakes betweenwet blankets of interlaced cellu: losic fibers. The wet blankets may besuitably formed in several manners, a preferred manner beingschematically indicated in FIG. 7, the equipment therein illustratedbeing a form of cylinder machine for forming webs of fibrous materials.This machine comprises a tank. 22 in which a slurry of fibers in watersuspension is placed as indicated at 23. The fibers employed may beformed from any suitable raw material of cellulosic nature such as wood,straw, ramie and others utilized to make paper or pulp products. Forreasons of economy the fibers are preferably provided by reclaimingledger or bond paper, newspapers or magazines, or mixtures of the same.The slurry is of the proper consistency for suction formation, such asabout three quarters of one percent fibers by weight to the weight ofwater employed. A driven suction cylinder 24 rotates about a horizontalaxis, with the lower portion of its periphery dipping into the slurry.The speed of rotation of the cylinder,.or the suction force, or theconsistency of the slurry, may be varied to determine the thickness of acontinuously formed blanket 25 of cellulosic fibers formed on thesurface of the cylinder by the application of suction through thescreen, or wire surface thereof, the water so withdrawn being dischargedthrough the hollow hub 26 of the cylinder as is. well known in suchdevices. The slurry is replenished in proportion to the withdrawal offibers therefrom through a supply pipe 27. Suction is maintained toreduce free water and to hold the formed blanket of fibers on thesurface of the cylinder to the point indicated at 28, then the suctionis relieved and the blanket 25 is withdrawn from the surface of the drumby rolling it onto a mandrel 29 having trunnions 30 at its ends whichrest in slots 31 at the upper ends of arms 32 pivoted near the bottom ofthe tank on pivots 33. The arrangement is such that the mandrel placedin the slots 31 rests against the surface of the cylinder, then theleading edge of a blanket is started around the mandrel by well-knownmeans available for this purpose, or manually. As soon as the blanket iswrapped around the mandrel at least once it will continue to spirallywind itself onto the mandrel to the desired extent, whereupon the rollof blanket is cut loose from the cylinder. Preferably this occurs whenthe size of the roll of blanket on the mandrel has increased to such anextent that one of the arms 32 engages a switch 35 which stops thesuction machine and actuates a bell or other alarm. The operator is thusmade aware that the machine has formed a roll of the desired size, andthe machine and supply of pulp thereto are automatically stopped bycontrol means (not shown) until the finished roll is removed and a newmandrel brought into position. The finished rolls of blanket materialare utilized in the sandwich forming machine of FIG. 8.

In FIG. 8 it is seen that the conveyor 19 brings the coated veneerflakes 21 into a forming bin having a front wall 36, a rear wall 37 andside walls 40, the side walls being provided with openings 41 throughwhich the conveyor belt 19 passes. A stretch of conveyor belt betweenthe side walls is horizontal and no guards are provided to hold theveneer flakes on the belt. The front wall 36 is provided with a narrow,horizontal slot 42 adjacent its lower edge, and the rear wall 37 isprovided with a wide, horizontal slot 43 adjacent its lower edge. Amovable succession of caul plates 44, slightly spaced from each other,forms a horizontal bottom wall of the forming bin. These caul paltes maybe of any suitable metal of suflicient rigidity to maintain planesurfaces, being preferably formed of an aluminum alloy and being aboutone quarter inch in thickness. They are fed endwise along the bottom ofthe bin by chain conveyors 45 having lugs 46 thereon which engage therear edges of the caul plates and space them about one half inch apart.The caul plates are preferably about two inches wider and two incheslonger than the desired finished board. The width of the blanket 25 isthe same as the width, of the caul plates, in other words approximatelytwo inches wider than the finished product.

A first roll of wet blanket indicated at 47 is positioned,

on the caul plates 44 in advance of the wall 36. To achieve this, thetrunnions 30 of a mandrel on which a roll is formed are retained betweenupright bars 48 and rested on crossbars 49 whereby the roll may be heldin position above the caul plates. The mandrel 29 comprises antifrictionbearings (not shown) whereby when the leading edge of the wet blanket islaid upon a caul plate the friction of the blanket on the caul platecauses the blanket to be unrolled from the mandrel. Suitable brakingmeans (not shown) are employed to prevent the roll from overrunning. Thewet blanket 47 serves as conveyor upon which the veneer flakes orparticles within the bin are deposited and moved. Mounted above thestretch of the conveyor belt 19 within the forming bin there is ahorizontal, driven shaft 50 provided with radial arms 51 which support abroom 52 extending from side to side of the bin, or from edge to edge ofthe caul plates. The rate of revolution of the shaft 50 is such that thebroom sweeps the coated veneer flakes from the conveyor belt just at themoment when the leading veneer flakes reach the far side wall, withoutallowing any veneer flakes to pass through the bin. That is, theinterval between sweeping movements of the broom and forward movement ofthe belt conveyor 19 are so synchronized that particles on the beltconveyor will move from the entrance to the bin to the opposite side ofthe bin in one broom sweeping interval. The veneer flakes fall freelythrough the space within the box, fluttering as they fall since they arequite light. Gentle airstreams are blown through ducts 53 toward the endwalls 36 and 37 for a purpose to be explained.

The layer of veneer flakes is built up to a depth of several inches, theexact depth depending upon the thickness desired for the finishedproduct. The air blowing toward the end walls 36 and 37 causes thenarrower veneer flakes to be blown toward the ends of the bin. Thus thenarrower veneer flakes which are blown toward the entering end wall 36are laid down as a layer of fines on the surface of the lower wetblanket 47 as it enters the bin. The speed of the conveyor chains 45 issuch that an interleaved mass 54 of coated veneer flakes is built up tothe desired thickness in the form of a wedge of material with itsmaximum height near the exit end wall 37, and the ail-streams directedtoward the end wall cause more fines to be deposited as the upper layerof the mass 54 as it leaves the forming bin, It is to be appreciatedthat this result will come about regardless of whether the veneer flakesare sliced on the diagonal of the blocks or vertically with respect tothe blocks. More such fines will be created if diagonal slicing isemployed. However, a certain amount will be formed if vertical slicingis employed since the veneer flakes are so thin that a number of themare split into variable widths as the veneer flakes travel through theduct 13 and the adhesive tumbling machine.

A pair of endless side belts 55 mounted upon vertical rollers 56 arepositioned at the sides of the bin with their adjacent flights passingthrough slots in the end walls and extending inside of the walls 40,these belts being driven in unison with the caul plate conveyor so thatthe sides of the mass of veneer flakes are progressed forwardly withoutbeing disturbed. The side portions of the mass extending beyond the caulplates are supported upon a pair of endless belts 57 passing aboutrollers 58, these belts also moving in unison with the conveyor 45.

As the lower wet blanket 47 of cellulosic fiber and interleaved mass 54of the coated veneer flakes emerge from the forming bin, an upper wetblanket 70 of cellulosic material is positioned thereon by the followingmeans. A second roll of blanket material is positioned above a drivenpressure roll 71 which rests upon the material. The trunnions 30 of theroll of material are guided between bars 72 and rest on crossbars 73.The pressure roll 71 is provided with trunnions 74 which are likewiseguided by the bars 72, but the roll is free to rise and fall, being heldfrom falling too far by stops 75. The pressure roll weighs about 600pounds so that the pack of material is greatly compressed. The wetblanket passes around the pressure roll and is laid thereby upon theupper surface of the interleaved veneer flake mass 54. The weight of theroll 71 is such that a mass of interleaved veneer flakes four inchesdeep is compressed to about two inches in thickness, but springs back toabout three inches in thickness as it leaves the roll. The roll 71 isdriven by suitable means (not shown) at the same peripheral speed as thespeed of the conveyor 45.

The material on the caul plate leaves the forming bin in the form of anendless ribbon and is thereafter cut into sections of appropriate lengthby means guided to cut the ribbon transversely above the spaces betweenadjacent caul plates as set forth in the above-identified ap plicationSerial No. 573,897, the separated mats being thereafter consolidated asdescribed in said application. After consolidation, the edges of theconsolidated board products are trimmed to form panels of a desiredsize.

Having illustrated and described a form of the present invention, it isto be appreciated that variations in arrangement and detail thereof willreadily occur to those skilled in the art. I claim all suchmodifications as come within the true spirit and scope of the appendedclaims as being my invention.

I claim:

1. Apparatus for forming a continuous ribbon of loosely matted,cellulosic particles from which board materials may be made comprising afirst horizontally disposed conveyor of a type suitable to support amass of loosely deposited cellulosic particles, at second horizontallydisposed conveyor extending transversely with respect to said firstconveyor at an elevation above said first conveyor, means to deposit astream of particles on said second conveyor, and a broom extendingsubstantially the width of said first conveyor sweeping across saidsecond conveyor at intervals, said broom and said second conveyor beingso synchronized that particles on said second conveyor above one edge ofsaid first conveyor will move to a point above the other edge of saidfirst conveyor during one broom sweeping interval, whereby said broomwill remove the particles therefrom and scatter them uniformly from sideto side of said first conveyor.

2. Apparatus for forming a continuous ribbon of loosely matted,cellulosic particles from which board materials may be made comprising afirst, continuously moving, horizontally disposed conveyor of a typesuitable to support a mass of loosely deposited cellulosic particles, asecond, continuously moving, horizontally disposed conveyor extendingtransversely with respect to said first conveyor at an elevation abovesaid first conveyor, means to deposit a regular stream of particles onsaid second conveyor, and a broom extending substantially the width ofsaid first conveyor sweeping across said second conveyor at regularintervals, said broom and said second conveyor being so synchronizedthat particles on said second conveyor above one edge of said firstconveyor will move to a point above the other edge of said firstconveyor during one broom sweeping interval, whereby said broom willremove the particles therefrom and scatter them uniformly from side toside of said first conveyor.

3. Apparatus for forming a continuous ribbon of loosely matted,cellulosic particles from which boardlike panels may bemade comprising afirst horizontally disposed conveyor, a succession of caul platesdisposed horizontally and in end-to-end relation on said first conveyor,a second conveyor extending transversely with respect to said firstconveyor at an elevation above said first conveyor, means to deposit auniform stream of cellulosic particles on said second conveyor, and abroom extending substantially the width of said caul plates sweepingacross said second conveyor at regular intervals, said broom and saidsecond conveyor being so synchronized that particles on said secondconveyor above one edge of said caul plates will move to a point abovethe other edge of said caul plates during one broom sweeping interval,whereby said broom will remove the particles therefrom and scatter themuniformly from side to side of said caul plates.

4. Apparatus for forming a continuous ribbon of loosely matted,cellulosic particles from which boardlike panels may be made comprisinga first, constantly moving conveyor, a succession of caul platesdisposed horizontally and in end-to-end relation on said first conveyor,a second constantly moving conveyor extending transversely with respectto said first conveyor at an elevation above said first conveyor, meansto deposit a uniform stream of cellulosic particles on said secondconveyor, a broom extending substantially the width of said caul platessweeping across said second conveyor at regular intervals, said broomand said second conveyor being so synchronized that particles on saidsecond conveyor above one edge of said caul plates will move to a pointabove the other edge of said caul plates during one broom sweepinginterval, whereby said broom will remove the particles therefrom andscatter them uniformly from side to side of said caul plates, and meansto vary the rate of deposit of said particles on said second conveyorwhereby to control the thickness of the ribbon formed on said caulplates.

5. Apparatus for forming a continuous ribbon of loosely matted,cellulosic particles having substantially uniform thickness throughoutcomprising a first conveyor including an endless succession ofhorizontally disposed caul plates, bin means defining a verticallyenclosed space above said first conveyor, a second conveyor of the belttype extending transversely with respect to said first conveyor at anelevation above said first conveyor, said bin means having openings inopposed walls thereof through which said belt-type conveyor extends,means to deposit cellulosic particles uniformly and continuously on saidsecond conveyor, and a broom extending from side to side of said binmeans sweeping across said second conveyor at regular intervals, themovement of said broom and second conveyor being so synchronized thatparticles on said second conveyor entering the bin through the openingin one opposed wall will move to the other opposed wall in one broomsweeping interval, whereby the particles are scattered into said binmeans uniformly from side to side thereof, without any particles passingthrough said bin means on said second conveyor.

6. Apparatus for forming a continuous ribbon of loosely matted,cellulosic particles having substantially uniform thickness throughoutcomprising a first conveyor including an endless succession ofhorizontally disposed caul plates, bin means including opposed end andside walls defining a vertically enclosed space above said firstconveyor, a second conveyor of the belt type extending transversely withrespect to said first conveyor at an elevation above said firstconveyor, said side walls having openings through which said belt-typeconveyor extends, means to deposit cellulosic particles uniformly andcontinuously on said second conveyor outside of said bin means, a broomextending from side to side of said bin means sweeping across saidsecond conveyor at regular intervals, the broom sweeping interval beingsynchronized with the rate of travel of said second conveyor whereby thebroom sweeps the particles from said second conveyor at the moment theleading particles reach the far side wall of said bin means towardswhich the leading particles are moving, without allowing any particlesto pass through said bin means, whereby all of the particles on saidsecond eonveyor within said bin means 'are'rernoved therefrom andscattered into said bin means uniformly transversely from side to sidethereof, and means disposed within said 'bin means' to direct finercellulosic particles toward said end walls.

References Cited in the file of this patent UNITED STATES PATENTS

1. APPARATUS FOR FORMING A CONTINUOUS RIBBON OF LOOSELY MATTED,CELLULOSIC PARTICLES FROM WHICH BOARD MATERIALS MAY BE MADE COMPRISING AFIRST HORIZONTALLY DISPOSED CONVEYOR OF A TYPE SUITABLE TO SUPPORT AMASS OF LOOSELY DEPOSITED CELLULOSIC PARTICLES, A SECOND HORIZONTALLYDISPOSED CONVEYOR EXTENDING TRANSVERSELY WITH RESPECT TO SAID FIRSTCONVEYOR AT AN ELEVATION ABOVE SAID